the-mews/SPEC.md

The Mews

Project layout

• app/ — Flutter application (main codebase)
• mews-spec/ — Mews Profile definition files
• nix-android-sdk/ — Nix flake providing the Android SDK for devbox

Flutter version: 3.41.9-sdk-links (keep in sync with devbox.json).

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Product spec

What it is

A Flutter browser/client for Mews Pages (see mews-spec).

Approach

Local-first: all data is stored locally in a Drift database. Network operations are secondary and never block local functionality.

Architecture directives

Keep files small and focused.

Layer separation

• presentation/ — rendering, input, gestures, navigation.
• application/actors/ — isolate-backed actors for CPU/IO work (image processing, export, file I/O).
• application/controllers/ — plain coordinators that own signals and handle synchronous UI commands.
• database/ — Drift tables, DAOs, queries.
• Signals expose UI-consumable state derived from the application layer.
• No business logic in widgets.

State management — Signals

• Use the signals package for reactive UI state.
• Widgets observe signals and dispatch actions to the application layer.
• Derived UI state should be computed, not manually synchronized.
• Do not duplicate state across multiple signals.

Business logic — Actor Model (actors package)

Use the actors package only where Dart Isolate isolation is genuinely useful: CPU-heavy work, blocking I/O, or tasks that must not block the UI thread. Do not use it for pure UI state or simple synchronous coordination.

Rules for all actors and coordinators:

• Model interactions as explicit sealed command types.
• No business logic in widgets — dispatch commands to the application layer.
• Keep classes small and focused; avoid large catch-all actors.
• Pass references explicitly when communication is needed.

Isolate constraint: The actors package runs handlers in separate Dart Isolates. Handlers cannot directly update signals on the main isolate. Isolate-backed actors must return results via message passing; the calling code applies results to signals.

Persistence — Drift

• Use drift for all tables, DAOs, and queries.
• Keep database definitions in database/ separate from UI code.

v1 reader UI

The v1 client presents one reader screen:

• An address field pinned at the top; it hides when the reader scrolls down and returns when they scroll up or reach the top. Its leading icons open the settings page and, on pointer platforms, go back and forward. Its trailing icons reload the page, subscribe to the site, and bookmark the page; subscribing is offered only on a page that carries dated links or declares an Atom feed.
• A swipe right goes back and a swipe left goes forward through the history stack. The whole empty margin beside the text column accepts the swipe, with a 40 px floor, so the gesture stays clear of selecting text. Touch devices navigate this way; pointer platforms get the address bar's buttons as well.
• Settings, history, bookmarks and subscriptions are internal pages under the mews: scheme. Each is built as an ordinary Mews document and rendered by the same renderer as a fetched page, so it joins the history stack and the swipe transitions. A setting is a link: following mews:setting/<group>/<value> applies the value and rerenders the page in place without adding a history entry.
• Fonts are bundled, and v1 ships Atkinson Hyperlegible. Adding a font is one TTF in app/assets/fonts/, one fonts entry in app/pubspec.yaml, one option on the settings page, and one label in app/locales/en-US/main.ftl.